In a conventional navigation system, the current location of a vehicle that is a host vehicle is detected by a Global Positioning System (GPS) device, for example. Map data is read out from a data storage portion, and a map screen is formed on a display unit. The host vehicle current location, a map of the area surrounding the host vehicle location, and the like are displayed on the map screen. Therefore, a driver, can drive the vehicle guided by the host vehicle location displayed on the map screen.
When the driver inputs a destination and sets search conditions, route search processing is executed based on the search conditions, and a route to the destination from a point of departure, which is expressed as the current location, is determined utilizing the map data. A specified route is displayed on the map screen together with the host vehicle location. Guidance along the specified route, that is, route guidance, is executed. Therefore, the driver is assisted in driving the vehicle along the specified route that is displayed.
In route guidance, when there is a specific intersection at which the vehicle must turn right or left, route guidance is executed, such as by voice output, for example, before the vehicle arrives at the intersection, which is termed a “guidance intersection”. In order for route guidance to be executed, one or more route guidance points are set at locations at predetermined distances in advance of the guidance intersection along the specified route. When the vehicle arrives at the route guidance points, route guidance with a content that is set in advance for each of the route guidance points is output by voice. (Refer to Patent Document 1, for example.)    [Patent Document 1] Japanese Patent Application Publication No. JP-A-6-295399